A so-called push-type terminal block has a push-type lever, an insertion hole and a connecting terminal therein. A cable conductor or a lead terminal attached to an end of a cable may be inserted into the insertion hole and connected to the connecting terminal. Such a push-type terminal block is, for example, used on the back side of an audio instrument and, in many cases, a plurality of the terminal blocks are aligned. For example, Japanese Unexamined Patent Publication (Kokai) No. 7-183059 describes that “When a lead “A” is connected to a first clamp portion 20, as shown in FIG. 3(b), a lever 3 is inclined on a seat member 2 about a rear edge 15a of a pressure contact portion 15 in order to raise a sliding shaft 4. Therefore, first and second holes 5 and 13 are aligned and lead “A” may be inserted into holes 5 and 13”.
A terminal block, having a movable portion such as a lever, usually has a coil spring for biasing the lever in a certain direction. For example, Japanese Unexamined Patent Publication (Kokai) No. 3-147216 describes that “As shown in FIG. 3(), a spring stopper plate 11 has a raised portion 22 on which a rear end of a coil spring 8 is hooked, and then, as shown in FIG. 3(), spring stopper plate 11 is bent so that the plate closes a spring insertion hole 9 of a case 1, whereby raised portion 22 pushes coil spring 8 forward”.
Japanese Unexamined Patent Publication (Kokai) No. 61-136431 describes that “As shown in FIG. 3, when a return spring 15 is assembled in a direction C, return spring 15 may be smoothly assembled without being jammed in a gap D, by means of a projecting column 21 arranged in a containing portion 14”.
In recent years, a terminal block such as a push-type terminal block is required to be more compact because an apparatus including the terminal block becomes downsized and complicated. Therefore, each component constituting the terminal block is inevitably required to be downsized. Concretely, a push lever for opening an insertion hole of each terminal and a coil spring which biases the push lever in the anti-push direction are required to be more compact. On the other hand, the lever and the coil spring are usually assembled manually, therefore, such compact lever or coil spring makes such a manual working troublesome. In particular, the coil spring is usually compressed when it is positioned in a housing and engaged with the lever. The compressed spring may be undesirably apart from a hand of an operator due to a repulsive force of the spring.